CN103575979A - Method for digital measuring of alternating current frequency - Google Patents
Method for digital measuring of alternating current frequency Download PDFInfo
- Publication number
- CN103575979A CN103575979A CN201210261928.6A CN201210261928A CN103575979A CN 103575979 A CN103575979 A CN 103575979A CN 201210261928 A CN201210261928 A CN 201210261928A CN 103575979 A CN103575979 A CN 103575979A
- Authority
- CN
- China
- Prior art keywords
- frequency
- sampled
- point
- integration
- sampled point
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Measuring Frequencies, Analyzing Spectra (AREA)
Abstract
The invention discloses a method for digital measuring of alternating current frequency. A digital integration and interpolation mode is used for processing continuous digital sampling signals, the virtual occurrence time of an integral start point P1 and the virtual occurrence time of an integral end point k which is acquired according to an interpolation mode after the signals cross a positive peak and a negative peak are used for calculating the zero point of electrical signals, the frequency or the period of the electrical signals are calculated through the zero crossing point of the electrical signals, then the zero point of the electric signals can be calculated through the sampling occurrence time of P1 and the virtual occurrence time of k, and the frequency or the period of the electrical signals can be calculated through the zero crossing point of a series of electrical signals. According to the method, low frequency signals do not need to be converted into square waves, the method is particularly suitable for frequency measuring of low-frequency sinusoidal signals, system detecting is convenient, hardware cost is low, the anti-jamming capability of a system is high, the method is simply and reasonably achieved, and data are accurate and reliable.
Description
Technical field
The present invention relates to a kind of method of digitized measurement ac frequency, also can be for the frequency measurement of fixed frequency or the little Low Frequency Sine Signals of frequency change, triangular signal, sawtooth signal etc.
Background technology
In daily life, production run, usually need the frequency of monitor signal.In the frequency measurement method of existing low frequency signal, be mostly low frequency signal first by shaping circuit, to form square wave, detect the time interval T of adjacent two rising edges of square wave or negative edge, ask inverse to draw frequency, but the antijamming capability of this method is poor.In addition also have the method for some software measurement frequencies, such as: zero friendship method, analytical method, error minimize principle class algorithm, DFT class algorithm, quadrature remove modulation method etc.These algorithms are easy to realize a bit, but because precision is compared with low and can not drop into practicality; The measurement effect of some algorithm is pretty good, but can not drop into practicality because operand is excessive.Industry needs be a kind of can practicality and measuring accuracy method more accurately.
Summary of the invention
Technical matters to be solved by this invention is the excessive shortcoming of operand in the not accurate enough or measuring process of the frequency measurement accuracy for prior art low and medium frequency electric signal, propose a kind of method of digitized measurement ac frequency, the method also can be for the frequency measurement of fixed frequency or the little Low Frequency Sine Signals of frequency change, triangular signal, sawtooth signal etc.
The present invention is for solving the problems of the technologies described above by the following technical solutions:
The party's ratio juris is to adopt the mode of digital integration interpolation to process continuous digital sampled signal, chooses a sampled point P after signal is crossed positive negative peak
1as integration starting point, in follow-up sampled point, can there are two continuous like this some P
iand P
i+1if, from P
1to P
idigital integration numerical value and from P
1to P
i+1the product of digital integration numerical value while being less than or equal to zero, can be at P
iand P
i+1between by the mode of interpolation, obtain an integration end point k, the condition of obtaining of k is from P
1digital integration to k is 0.Can be by P
1sampling time of origin and the virtual time of origin of k zero point of calculating electric signal, frequency or the cycle of by the zero crossing of series of electrical signals, being calculated electric signal; Concrete steps are as follows:
Step 1), samples to tested electric signals, obtains the sampled value of tested electric signals, then generates sampled signal;
Step 2), in the sampled signal of tested electric signals, select m the sampled point discharging in order after the cycle of tested electric signals is crossed any one peak value on the sampling time, the sampling time of establishing this m sampled point is respectively t
1, t
2... t
i, t
i+1... t
m, sampled value is respectively x
1, x
2... x
i, x
i+1... x
m, wherein i, m are natural number and 1≤i<m;
Step 3), makes S
ifor from the 1st sampled point (x
1, t
1) to i sampled point (x
i, t
i) digital integration, S
i+1for from the 1st sampled point (x
1, t
1) to i+1 sampled point (x
i+1, t
i+1) digital integration; Work as S
iand S
i+1product be less than or equal at 0 o'clock, between i sampled point and i+1 sampled point, by the mode of interpolation, obtain a digital integration end point k, make from the 1st sampled point (x
1, t
1) to integration end point (x
k, t
k) digital integration be zero, calculate the virtual time of origin t of integration end point k
k;
Step 4), calculate the zero crossing time:
Step 5), repeating step 2) obtain several zero crossings time: T to step 4)
z1, T
z2, T
z3... T
zj, T
zj+1, T
zj+2... T
zn, wherein, j=1,2 ... n, the cycle of tested ac signal: T
pj=T
zj+2-T
zjor T
pj=2 * (T
zj+1-T
zj), the frequency of tested ac signal:
Or:
Further, the method for a kind of digitized measurement ac frequency of the present invention, tested electric signals being sampled described in step 1) is constant duration sampling or not constant duration sampling.
Further, the method for a kind of digitized measurement ac frequency of the present invention, being sampled as described in step 1) sampled to the complete cycle ripple of tested electric signals.
Further, the method for a kind of digitized measurement ac frequency of the present invention, the Choice of described the 1st sampled point is: while not arriving zero point after the cycle of tested electric signals is crossed any one peak value, select a sampled point as the 1st sampled point.
Further, the method of a kind of digitized measurement ac frequency of the present invention, further comprising the steps of: repeating step 1) to step 5), to measure several cycles or the frequency values of tested electric signals, then to several cycles that obtain or frequency values, adopt the method for average to calculate final frequency.
Further, the method for a kind of digitized measurement ac frequency of the present invention, described digital integration mode comprises: trapezoidal integration or rectangular integration; Described interpolation method is: rectangle interpolation or trapezoidal interpolation.
The present invention adopts above technical scheme compared with prior art, has following technique effect:
1) traditional two contrary continuity points of zero friendship method symbolization are determined zero crossing, although algorithm clear physics conception is easily subject to the interference of harmonic wave, noise etc., measuring accuracy is low.For electric signal great majority, are symmetrical features, tested electric signals is crossed to the laggard row digital integration of peak value, by the mode of interpolation, obtain an integration end point, making the digital integration from integration starting point to integration end point is zero, the zero point of calculating electric signal by the sampling time of origin of integration starting point and the virtual time of origin of integration end point.After having determined the zero crossing of signal, can calculate frequency and the cycle of electric signal.Traditional zero friendship method of comparing, the antijamming capability of system has great raising, and the accuracy of frequency measurement also improves greatly.Even if experiment shows to have sneaked into larger harmonic wave, white noise in electric signal, the degree of accuracy of measurement is also very high.
2) the method is very convenient simple and direct when calculating, and is applicable to using under embedded system.
Accompanying drawing explanation
Fig. 1 adopts the mode of rectangular integration, rectangle interpolation to calculate the virtual time of origin of integration end point, and obtains the schematic diagram of zero crossing;
Fig. 2 adopts the mode of trapezoidal integration, trapezoidal interpolation to calculate the virtual time of origin of integration end point, and obtains the schematic diagram of zero crossing;
Fig. 3 adopts the mode of trapezoidal integration, rectangle interpolation to calculate the virtual time of origin of integration end point, and obtains the schematic diagram of zero crossing;
Fig. 4, after ac signal is sampled, carries out rectangular integration, rectangle interpolation after each peak value, obtains the schematic diagram of zero crossing computation period;
Fig. 5, after ac signal is sampled, carries out trapezoidal integration, trapezoidal interpolation after each peak value, obtains the schematic diagram of zero crossing computation period;
Fig. 6, after ac signal is sampled, carries out trapezoidal integration, rectangle interpolation after each peak value, obtains the schematic diagram of zero crossing computation period.
Embodiment
Below in conjunction with accompanying drawing, technical scheme of the present invention is described in further detail:
Essence of the present invention is to adopt the mode of digital integration interpolation to process continuous digital sampled signal, chooses a sampled point P after signal is crossed positive negative peak
1as integration starting point, in follow-up sampled point, can there are two continuous like this some P
iand P
i+1if, from P
1to P
idigital integration numerical value and from P
1to P
i+1the product of digital integration numerical value be less than or equal at 0 o'clock, can be at P
iand P
i+1between by the mode of interpolation, obtain an integration end point k, the condition of obtaining of k is from P
1digital integration to k is 0.Can be by P
1sampling time of origin and the virtual time of origin of k zero point of calculating electric signal, frequency or the cycle of by the zero crossing of series of electrical signals, being calculated electric signal.Here so-called digital integration has following several mode: trapezoidal integration, rectangular integration mode; Here so-called interpolation has rectangle interpolation, trapezoidal interpolation method.
Principle of the present invention describes by measuring two all wave frequencies of ac signal.
Specific embodiment of the invention process is as follows:
1. pair tested electric signals is sampled, and described here is sampled as the sampling that complete cycle ripple is carried out.Can be constant duration sampling, can be also not constant duration sampling.
2. after tested electric signals is crossed positive negative peak, select several sampled points discharging in order on the sampling time, the sampling time of supposing each sampled point is t
i, sampled value is x
i, i>=1, makes S
ifor from point (x
1, t
1) digital integration of ordering to i;
3. if S
iand S
i+1product be less than or equal to 0, can between i point and i+1 point, by the mode of interpolation, obtain an integration end point k, make from point (x
1, t
1) to the digital integration of some k, be zero, can calculate the virtual time of origin t of a k
k;
4. the computing formula of the zero crossing time after selected peak value is as follows:
5. calculating the concrete operations of zero crossing time can be referring to Fig. 1, Fig. 2, Fig. 3.Fig. 1 adopts the mode of rectangular integration, rectangle interpolation to calculate the virtual time of origin of integration end point, and obtains the schematic diagram of zero crossing.In Fig. 1 from t
1start digital integration, t
kthe virtual time of origin of the integration end point obtained of interpolation, in figure from t
1to t
kdigital integration be 0.T
zto calculate the zero crossing obtaining.Fig. 2 adopts the mode of trapezoidal integration, trapezoidal interpolation to calculate the virtual time of origin of integration end point, and obtains the schematic diagram of zero crossing.In Fig. 2 from t
1start digital integration, t
kthe virtual time of origin of the integration end point obtained of interpolation, in figure from t
1to t
kdigital integration be 0.T
zto calculate the zero crossing obtaining.Fig. 3 adopts the mode of trapezoidal integration, rectangle interpolation to calculate the virtual time of origin of integration end point, and obtains the schematic diagram of zero crossing.In Fig. 3 from t
1start digital integration, t
kthe virtual time of origin of the integration end point obtained of interpolation, in figure from t
1to t
kdigital integration be 0.T
zto calculate the zero crossing obtaining.If purely adopt trapezoidal integration, when carrying out interpolation calculation, there is calculated amount situation bigger than normal.Fig. 3 adopts trapezoidal integration when starting integration, but when carrying out interpolation arithmetic, has adopted the method for rectangle interpolation, and the object of doing is like this to reduce the complexity of computing.For obtaining measurement result comparatively accurately, the height of establishing this rectangle in the calculating of accompanying drawing is the mean value of two sampled points of vicinity.
6. repeat above-mentioned steps, obtain several zero crossings time, T
z1, T
z2, T
z3... T
zj, T
zj+1, T
zj+2... T
zn, the cycle of tested ac signal: T
pj=T
zj+2-T
zjor T
pj=2 * (T
zj+1-T
zj), the frequency of tested ac signal:
Or:
Pair electric signal after sampling, near each zero point, calculate and the figure of survey frequency as Fig. 4, Fig. 5, Fig. 6.What Fig. 4 adopted is the method for rectangular integration, rectangle interpolation, and what Fig. 5 adopted is the method for trapezoidal integration, trapezoidal interpolation, and what Fig. 6 adopted is the method for trapezoidal integration, rectangle interpolation.There are 4 zero crossings in the ac signal in Fig. 4, Fig. 5, Fig. 6, has therefore carried out four integrations and calculated.Soft dot in Fig. 4, Fig. 5, Fig. 6 on transverse axis is the zero crossing calculating, zero crossing successively: T
z1, T
z2, T
z3, T
z4.The cycle of this signal can be expressed as T
p=T
z3-T
z1or T
p=T
z4-T
z2or T
p=2 * (T
z2-T
z1) or T
p=2 * (T
z3-T
2) or T
p=2 * (T
z4-T
z3), frequency F
pt
pinverse.
8. repeat above-mentioned steps, measure several cycles or the frequency values of tested electric signals, then to several cycles that obtain or frequency values, adopt the method for average to calculate final frequency.
From accompanying drawing, can see, adopt the zero point of trapezoidal integration, zero point that trapezoidal method of interpolation obtains and actual signal the most approaching, adopt trapezoidal integration, zero point that rectangle method of interpolation obtains and the zero point of actual signal to have certain error, adopt the error at zero point of rectangular integration, zero point that rectangle method of interpolation obtains and actual signal maximum.Certainly along with the increase of sampling number, this error will be more and more less.Consider the feature of embedded system, preferred version is to adopt trapezoidal integration, the zero crossing of rectangle interpolation calculation signal.
In sum, the method for a kind of digitized measurement ac frequency involved in the present invention, does not need to convert ac signal to square wave, is particularly suitable for the frequency measurement of Low Frequency Sine Signals, and system is easy to detect, and hardware spending is little; The antijamming capability of system is very strong; Implement advantages of simple, data accurately, reliably; There is application prospect more widely.
Claims (6)
1. a method for digitized measurement ac frequency, is characterized in that: comprise the following steps:
Step 1), samples to tested electric signals, obtains the sampled value of tested electric signals, then generates sampled signal;
Step 2), in the sampled signal of tested electric signals, select m the sampled point discharging in order after the cycle of tested electric signals is crossed any one peak value on the sampling time, the sampling time of establishing this m sampled point is respectively t
1, t
2... t
i, t
i+1... t
m, sampled value is respectively x
1, x
2... x
i, x
i+1... x
m, wherein i, m are natural number and 1≤i<m;
Step 3), makes S
ifor from the 1st sampled point (x
1, t
1) to i sampled point (x
i, t
i) digital integration, S
i+1for from the 1st sampled point (x
1, t
1) to i+1 sampled point (x
i+1, t
i+1) digital integration; Work as S
iand S
i+1product be less than or equal at 0 o'clock, between i sampled point and i+1 sampled point, by the mode of interpolation, obtain a digital integration end point k, make from the 1st sampled point (x
1, t
1) to integration end point (x
k, t
k) digital integration be zero, calculate the virtual time of origin t of integration end point k
k;
Step 4), calculate the zero crossing time:
Step 5), repeating step 2) obtain successively several zero crossing time: T to step 4)
z1, T
z2, T
z3... T
zj, T
zj+1, T
zj+2... T
zn, wherein, j=1,2 ... n, the cycle of tested ac signal: T
pj=T
zj+2-T
zjor T
pj=2 * (T
zj+1-T
zj), the frequency of tested ac signal:
Or:
2. the method for a kind of digitized measurement ac frequency according to claim 1, is characterized in that: described in step 1), tested electric signals being sampled is constant duration sampling or not constant duration sampling.
3. the method for a kind of digitized measurement ac frequency according to claim 1, is characterized in that: being sampled as described in step 1) sampled to the complete cycle ripple of tested electric signals.
4. the method for a kind of digitized measurement ac frequency according to claim 1, is characterized in that: the Choice of described the 1st sampled point is: while not arriving zero point after the cycle of tested electric signals is crossed any one peak value, select a sampled point as the 1st sampled point.
5. according to the method for a kind of digitized measurement ac frequency described in any one in claim 1 to 4, it is characterized in that: further comprising the steps of: repeating step 1) to step 5), measure several cycles or the frequency values of tested electric signals, then to several cycles that obtain or frequency values, adopt the method for average to calculate final frequency.
6. according to the method for a kind of digitized measurement ac frequency described in any one in claim 1 to 4, it is characterized in that: described digital integration mode comprises: trapezoidal integration or rectangular integration; Described interpolation method comprises: rectangle interpolation or trapezoidal interpolation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210261928.6A CN103575979B (en) | 2012-07-26 | 2012-07-26 | A kind of method of digitized measurement ac frequency |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210261928.6A CN103575979B (en) | 2012-07-26 | 2012-07-26 | A kind of method of digitized measurement ac frequency |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103575979A true CN103575979A (en) | 2014-02-12 |
| CN103575979B CN103575979B (en) | 2016-03-02 |
Family
ID=50048186
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210261928.6A Expired - Fee Related CN103575979B (en) | 2012-07-26 | 2012-07-26 | A kind of method of digitized measurement ac frequency |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103575979B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105259409A (en) * | 2015-10-13 | 2016-01-20 | 安徽节源环保科技有限公司 | Power signal frequency calculating method based on zero-crossing time-domain characteristic |
| CN107561306A (en) * | 2017-08-17 | 2018-01-09 | 湖南纬拓信息科技有限公司 | Winding motor rotating speed measurement method based on rotor current |
| CN108957133A (en) * | 2018-08-13 | 2018-12-07 | 国网浙江省电力有限公司绍兴供电公司 | The dynamic evaluation of substation capacitors sample frequency and choosing method |
| CN110873822A (en) * | 2018-09-02 | 2020-03-10 | 青岛鼎信通讯股份有限公司 | Method for calculating frequency in alternating current sampling of feeder terminal |
| CN113049872A (en) * | 2021-02-02 | 2021-06-29 | 厦门大学 | Electric signal zero detection method for multiple times of low-frequency current ripple suppression |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57175964A (en) * | 1981-04-24 | 1982-10-29 | Toshiba Corp | Frequency detector |
| US5321350A (en) * | 1989-03-07 | 1994-06-14 | Peter Haas | Fundamental frequency and period detector |
| CN1815248A (en) * | 2005-02-02 | 2006-08-09 | 艾默生网络能源***有限公司 | Alternating Current Frequency Monitoring Method |
| EP1884838A1 (en) * | 2006-07-28 | 2008-02-06 | Samsung Electronics Co., Ltd. | Phase Detecting Device, Phase Control Device including the Phase Detecting Device, and Fuser Control Device including the Phase Control Device |
| CN101871965A (en) * | 2010-06-11 | 2010-10-27 | 威胜集团有限公司 | Method for detecting zero crossing time, frequency and phase difference of power sinusoidal signals |
| CN102033161A (en) * | 2010-12-17 | 2011-04-27 | 南京邮电大学 | Frequency measuring method of alternating current signal |
-
2012
- 2012-07-26 CN CN201210261928.6A patent/CN103575979B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57175964A (en) * | 1981-04-24 | 1982-10-29 | Toshiba Corp | Frequency detector |
| US5321350A (en) * | 1989-03-07 | 1994-06-14 | Peter Haas | Fundamental frequency and period detector |
| CN1815248A (en) * | 2005-02-02 | 2006-08-09 | 艾默生网络能源***有限公司 | Alternating Current Frequency Monitoring Method |
| EP1884838A1 (en) * | 2006-07-28 | 2008-02-06 | Samsung Electronics Co., Ltd. | Phase Detecting Device, Phase Control Device including the Phase Detecting Device, and Fuser Control Device including the Phase Control Device |
| CN101871965A (en) * | 2010-06-11 | 2010-10-27 | 威胜集团有限公司 | Method for detecting zero crossing time, frequency and phase difference of power sinusoidal signals |
| CN102033161A (en) * | 2010-12-17 | 2011-04-27 | 南京邮电大学 | Frequency measuring method of alternating current signal |
Non-Patent Citations (1)
| Title |
|---|
| 杨永标 等: "一种实用的高精度频率测量方法", 《继电器》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105259409A (en) * | 2015-10-13 | 2016-01-20 | 安徽节源环保科技有限公司 | Power signal frequency calculating method based on zero-crossing time-domain characteristic |
| CN105259409B (en) * | 2015-10-13 | 2017-11-28 | 安徽节源环保科技有限公司 | A kind of frequency power signal computational methods based on zero passage time domain specification |
| CN107561306A (en) * | 2017-08-17 | 2018-01-09 | 湖南纬拓信息科技有限公司 | Winding motor rotating speed measurement method based on rotor current |
| CN107561306B (en) * | 2017-08-17 | 2020-04-14 | 湖南纬拓信息科技有限公司 | Method for measuring rotating speed of wound-rotor motor based on rotor current |
| CN108957133A (en) * | 2018-08-13 | 2018-12-07 | 国网浙江省电力有限公司绍兴供电公司 | The dynamic evaluation of substation capacitors sample frequency and choosing method |
| CN110873822A (en) * | 2018-09-02 | 2020-03-10 | 青岛鼎信通讯股份有限公司 | Method for calculating frequency in alternating current sampling of feeder terminal |
| CN113049872A (en) * | 2021-02-02 | 2021-06-29 | 厦门大学 | Electric signal zero detection method for multiple times of low-frequency current ripple suppression |
| CN113049872B (en) * | 2021-02-02 | 2021-11-16 | 厦门大学 | Electric signal zero detection method for multiple times of low-frequency current ripple suppression |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103575979B (en) | 2016-03-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101806832B (en) | Measuring method for frequencies of low-frequency signals | |
| CN102033161B (en) | Frequency measuring method of alternating current signal | |
| CN102809687B (en) | Digital measurement method for alternating-current frequency | |
| CN102288821B (en) | Measuring method, measuring device, measuring procedure and carrier for phase difference of three-phase circuit | |
| CN103989462B (en) | The extracting method of a kind of pulse wave fisrt feature point and second feature point | |
| CN101813725B (en) | Method for measuring phase difference of low-frequency signals | |
| CN101833036B (en) | Method for measuring instantaneous phase of alternating current | |
| CN102095929B (en) | Method for rapidly measuring frequency of alternating-current signals | |
| CN102879639A (en) | Real-time frequency measuring method in power system | |
| CN103575979B (en) | A kind of method of digitized measurement ac frequency | |
| CN102135568B (en) | Period detection method and phase difference detection method for alternating current signal | |
| CN103941091A (en) | Power system HHT harmonious wave detection method based on improved EMD end point effect | |
| CN109752584B (en) | Method for measuring effective value of periodic signal | |
| CN102508031A (en) | Fourier series based measurement method of phase angle of partial discharge pulse | |
| CN109061345B (en) | Effective value measuring method and system suitable for power system | |
| CN105699738A (en) | PWM-based AC signal effective value measurement method | |
| CN103575981A (en) | Method for accurately measuring alternating current frequency | |
| CN102778606B (en) | Digital measurement method for instantaneous phase of alternating current | |
| CN102928666B (en) | Digital measurement method for phase difference of alternating current | |
| CN106970265B (en) | A method of harmonic parameters are estimated using the incomplete S-transformation of Multiple Time Scales | |
| CN105548711B (en) | A kind of multifrequency information filter recursive demodulation method | |
| CN104808055A (en) | Electrical signal frequency digitized measurement method | |
| CN108415880A (en) | A kind of line loss characteristic analysis method based on Sample Entropy and wavelet transformation | |
| CN102095936B (en) | Method for measuring phase difference of alternating-current electric signals quickly | |
| CN104808060A (en) | Method for digitally measuring the phase difference of electrical signals |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20140212 Assignee: Jiangsu Nanyou IOT Technology Park Ltd. Assignor: Nanjing Post & Telecommunication Univ. Contract record no.: 2016320000215 Denomination of invention: Method for digital measuring of alternating current frequency Granted publication date: 20160302 License type: Common License Record date: 20161118 |
|
| LICC | Enforcement, change and cancellation of record of contracts on the licence for exploitation of a patent or utility model | ||
| EC01 | Cancellation of recordation of patent licensing contract |
Assignee: Jiangsu Nanyou IOT Technology Park Ltd. Assignor: Nanjing Post & Telecommunication Univ. Contract record no.: 2016320000215 Date of cancellation: 20180116 |
|
| EC01 | Cancellation of recordation of patent licensing contract | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20160302 Termination date: 20180726 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |